The idea of a hypnotic riff as the prime mover of a piece of music has been around for a long time, whether you're talking about the Delta blues or music from Middle Eastern and African cultures.

I'm obsessed - not just interested, obsessed - with folk music, street music, the parallels between a country's street music and its so-called classical and intellectual music, the way certain scales have travelled right across the globe. All this ethnological and musical interaction fascinates me. Have you heard any trance music? That's the thing.

I believe every guitar player inherently has something unique about their playing. They just have to identify what makes them different and develop it.

Led Zeppelin didn't get that kind of Beatles screaming. We had a more sort of macho crowd. But I remember once in the early days of The Yardbirds, we were playing on an ice rink, and the stage was mobbed by screaming girls. I had my clothes torn off me. That's a really uncomfortable experience, let me tell you.

You can't buy time. Everything, for me, seems to be a race against time. Especially musically.

There's so many different styles and facets of the 360-degree musical sphere to listen to. From tribal to classical music, it's all there. If the bottom was to sag out of that, for God's sake, help us all.

The element of change has been the thing, really. We put out the first one, then the second... then a third LP totally different from them. It's the reason we were able to keep it together.